Chief among them was Great Britain's Bradley Wiggins, who followed up his achievement of winning the Tour de France just over a week earlier by taking victory in the men's Time Trial.
The Brit struck Olympic gold in his home town of London before declaring: 'It's never, ever going to get any better than that.'
The 32-year-old became the Tour's first British winner on July 22 and now has become the first man to win the yellow jersey and Olympic gold in the same year after an imperious performance in the 44km Time Trial at Hampton Court.
The success saw Wiggins claim a fourth Olympic gold and a seventh medal in all, and he admitted he could hardly believe it.
'To go out there today and put a performance like that together nine days after the Tour and win another Olympic title in another event, it is never, ever going to get any better than that,' Wiggins said.
'There is almost slight melancholy. I realised on the podium that that's probably it for me. I don't think anything is going to top that.'
Earlier, Alexandr Vinokurov began the programme in style when he triumphed in a dramatic men's Road Race to claim gold for Kazakhstan.
Vinokurov and Colombian Rigeberto Uran Uran broke clear in the final stages and the Kazakh launched his sprint with 400m to go, catching the Colombian by surprise, to triumph.
Afterwards he announced he would consider retiring at the top of his sport.
He said: 'It will be a nice way to finish off my career with a gold medal.'
The women's equivalent was won by Marianne Vos of the Netherlands, who took gold on The Mall after a thrilling climax to the women's Road Race.
The Dutch rider edged ahead at the end of a pulsating 140km race, which featured two climbs of Surrey's Box Hill.
There was also triumph for Kristin Armstrong of the USA, who successfully defended her Olympic Time Trial title at Hampton Court.
Afterwards, she admitted she had put her all into the race, saying: 'I just needed to give it everything.'